[0.16.32] Auto updater fails to update Factorio.exe

[Vatharian]

Bug applies to standalone portable Windows x64 non-steam version. For obvious reasons Steam is not affected.

I noticed the issue first at 0.16.32, and now it happened to me few times: when updating to .35, .36, .37 and now .38. It doesn't happens always! I'd say it's 50-50 chance of successful update. I play Factorio on 4 different PCs,

The auto updater downloads delta ZIP, unpacks it, and throws 'failed to update Factorio.exe, Access denied.' Game closes, and it's done.

I can't run the game again, since Factorio.exe is missing.

Workaround: Download full game install zip, unpack to game directory, play.

Likely culprit: There is either a bug in updater code, or it is violent interaction with antivirus locking the file (which is just bad design, but hey).
I am using Avast Pro, but I have my whole games folder added to exclude list and I disabled it fully on update 36 to 38 just a moment ago and it failed too.
I verified I am logged it, since I can download mods.

Suggested fix: make update atomic, copy-on-write, instead of switching the executable on-the-fly.

[Loewchen]

Post the log after a session with the issue.

[0mega]

Just happened to me when updating from 0.16.36, standalone version. I attached the log file.